Dilation of the annulus of the mitral valve prevents the valve leaflets from fully coapting when the valve is closed. Mitral regurgitation of blood from the left ventricle into the left atrium results in increased total stroke volume and decreased cardiac output, and ultimate weakening of the left ventricle secondary to a volume overload and a pressure overload of the left atrium.
US Patent Application 2004/0236419 to Milo describes methods for reconfiguring an atrioventricular heart valve that may use systems comprising a partial or complete annuloplasty rings proportioned to reconfigure a heart valve that has become in some way incompetent, a pair of trigonal sutures or implantable anchors, and a plurality of staples which may have pairs of legs that are sized and shaped for association with the ring at spaced locations along its length. These systems permit relative axial movement between the staples and the ring, whereby a patient's heart valve can be reconfigured in a manner that does not deter subtle shifting of the native valve components. Shape-memory alloy material staples may have legs with free ends that interlock following implantation. Annuloplasty rings may be complete or partial and may be fenestrated. One alternative method routes a flexible wire, preferably of shape-memory material, through the bights of pre-implanted staples. Other alternative systems use linkers of shape-memory material having hooked ends to interengage with staples or other implanted supports which, following implantation, decrease in effective length and pull the staples or other supports toward one another so as to create desired curvature of the reconfigured valve. These linkers may be separate from the supports or may be integral with them and may have a variety of shapes and forms. Various of these systems may be implanted non-invasively using a delivery catheter.
US 2007/0049942 to Hindrichs et al. describes remodeling a soft body tissue structure by shortening the distance between first and second portions of that tissue structure. First and second anchor structures are respectively implanted in the first and second portions of the tissue structure. These anchor structures are linked by a linking structure, the length of which between the anchor structures can be shortened to pull the tissue structure portions toward one another. Each of the anchor structures may include two screw structures that are driven into the associated tissue structure portion transverse to the linking structure and with a spacer between the two screws. The entire prosthesis can be implanted percutaneously if desired. An illustrative use of the prosthesis is to shorten the annulus of a patient's mitral valve, with at least a portion of the prosthesis implanted in the patient's coronary sinus.
The following patents and patent application publications may be of interest:    PCT Publication WO 07/136,783 to Cartledge et al.    PCT Publication WO 08/068,756 to Gross et al.    PCT Publication WO 10/004,546 to Gross et al.    PCT Publication WO 10/073,246 to Cabiri et al.    U.S. Pat. No. 5,306,296 to Wright et al.    U.S. Pat. No. 6,569,198 to Wilson et al.    U.S. Pat. No. 6,619,291 to Hlavka et al.    U.S. Pat. No. 6,764,510 to Vidlund et al.    U.S. Pat. No. 7,004,176 to Lau    U.S. Pat. No. 7,101,395 to Tremulis et al.    U.S. Pat. No. 7,175,660 to Cartledge et al.    US 2003/0050693 to Quijano et al    US 2003/0167062 to Gambale et al.    US 2004/0024451 to Johnson et al.    US 2004/0148021 to Cartledge et al.    US 2005/0171601 to Cosgrove et al.    US 2005/0288781 to Moaddeb et al.    US 2007/0016287 to Cartledge et al.    US 2007/0080188 to Spence et al.    US 2007/0219558 to Deutsch    US 2007/0282375 to Hindrichs et al.    US 2008/0262609 to Gross et al.    US 2010/0161041 to Maisano et al.    US 2010/0161042 to Maisano et al.    US 2010/0211166 to Miller et al.
The following articles may be of interest:    O'Reilly S et al., “Heart valve surgery pushes the envelope,” Medtech Insight 8(3): 73, 99-108 (2006)    Dieter RS, “Percutaneous valve repair: Update on mitral regurgitation and endovascular approaches to the mitral valve,” Applications in Imaging, Cardiac Interventions, Supported by an educational grant from Amersham Health pp. 11-14 (2003)